Nineteen men have appeared in court in South Africa charged with plotting to overthrow the government of the Democratic Republic of Congo.

The case recalls the doomed “Wonga Coup” plot led by Simon Mann which ended with the British mercenary spending three years in jail in oil-rich Equatorial Guinea. Similar to the 2004 debacle, the Congolese rebels, led by a naturalised US citizen, James Kazongo, sought financial backers in South Africa. They promised to pay them back from Congo’s mineral riches. The rebels told undercover police in South Africa that they were part of a group calling itself the Union of Nationalists for Renewal, and needed money, guns and training for their mercenary plan.

In an elaborate sting operation the rebels were told they would be taken to a farm in the remote Limpopo area and trained under the pretence of being an anti-rhino poaching unit. They were instead arrested.

There are numerous armed rebel groups already operating in the vasts of DR Congo, many of them financed in part by small pieces of the country’s mineral reserves estimated at $23 trillion (£14.6trn). President Joseph Kabila, who came to power after his coup-plotting father Laurent was himself assassinated, has been accused of auctioning off $500bn (£318bn) in mining concessions for a fraction of their worth.

There has been intense competition for Congolese resources with China and South Africa both undertaking major deals with the current government. South Africa’s President Jacob Zuma has been accused of favouring the notoriously corrupt Kabila regime and Congolese protesters picketed the hearing in Pretoria.